The purpose of this research is to delineate how new, computer-based medical imaging technologies in general, and the CT-scanner in particular, are altering the social context of radiology departments in community hospitals and are changing the tasks, roles, role relationships, and practices of radiologists and radiological technologists. While researchers and policy planners have given detailed attention to the economic and medical implications of new diagnostic technologies, almost no attention has been focused on how te technologies alter the social context of the settings in which they are used. As assessment of changes in the social context of medical practice brought about by these technologies should be of assistance to physicians and administrators who manage the use of the technologies, to medical educators who train personnel to operate the technologies, and to health service planners interested in how the quality of care is influenced by the context in which it is received. Designed as a year long ethnographic study of two radiology departments who will implement their first whole body CT-scanner three months after the start of the project, the research has two thrusts. On one had the study will document longitudinally the issues, processes, and stages by which a CT-scanner's operation develops over time into an unique technological subculture within a radiology department. On the other hand, the study is comparative in that it will assess how the social practices surrounding the new imaging modalities [eg. CT, ultrasound, special procedures (Digital Subtraction Angiography)] are similar to one another but differ from the social context surrounding older radiographic procedures. The data gathered by the researcher as a participant-observer in both research sites will be augmented by a number of quantitative studies of smaller scope, including as assessment of how the CT-scanners affect the structure of communications within the departments.